Knitting machine parts resistant to abrasion by yarn of cut-resistant fiber

Abstract

A knitting machine part which is resistant to abrasion caused by knitting a yarn of cut-resistant fiber contains: (i) a base substrate having at least one yarn-contacting region for contacting the yarn during the knitting process, and (ii) a coating disposed on the surface of the base substrate on at least the yarn-contacting region of the base substrate, wherein the coating contains titanium carbonitride having a carbon-to-nitrogen weight ratio of from about 1:4 to 4:1, preferably from about 1:1.5 to 1.5:1, most preferably about 1:1. The knitting machine part is preferably a knitting needle or a sinker. The cut-resistant yarn is preferably composed of at least one cut-resistant fiber formed from a fiber-forming polymer and a hard filler having a Mohs Hardness value of at least about 3, the hard filler being distributed in the fiber-forming polymer. The coated knitting machine part may also be used to knit conventional fibers and yarns, for example, fibers and yarns which are not cut-resistant, including abrasive fibers which are not cut-resistant.

What is claimed is: 
     
       1. A knitting machine part which is resistant to abrasion caused by knitting a yarn comprising a cut-resistant fiber, said knitting machine part comprising: (A) a base substrate having a surface and having at least one yarn-contacting region for contacting said yarn during the knitting process; and   (B) a coating disposed on the surface of at least said yarn-contacting region of said base substrate, wherein said coating comprises titanium carbonitride having a carbon-to-nitrogen weight ratio of from about 1:4 to about 4:1, further wherein said coating has a hardness sufficient to resist abrasion caused by knitting said yarn and said base substrate has a Rockwell-C Hardness value of from about 50 to about 55.   
     
     
       2. A knitting machine part according to claim 1, wherein the carbon-to-nitrogen weight ratio is from about 1:1.5 to about 1.5:1. 
     
     
       3. A knitting machine part according to claim 1, wherein the carbon-to-nitrogen weight ratio is about 1:1. 
     
     
       4. A knitting machine part according to claim 1, wherein said titanium carbonitride coating has been formed on the yarn-contacting region by a chemical vapor deposition process using a deposition temperature of from about 800° C. to about 1000° C. 
     
     
       5. A knitting machine part according to claim 1, wherein said coating has a thickness of at least about 2 microns. 
     
     
       6. A knitting machine part according to claim 1, wherein said base substrate is uniformly coated with said coating. 
     
     
       7. A knitting machine part according to claim 1, wherein said base substrate comprises an iron series metal or a hard sintered alloy. 
     
     
       8. A knitting machine part according to claim 1, wherein said coated base substrate comprises carbon steel or stainless steel, further wherein said coated base substrate has been subjected to a steel-annealing heat treatment process. 
     
     
       9. A knitting machine part according to claim 8, wherein said substrate comprises carbon steel having a carbon content of about 0.86% to about 0.95% by weight and a Rockwell-C Hardness of from about 50 to about 55. 
     
     
       10. A knitting machine part according to claim 1, wherein said knitting machine part is a knitting needle. 
     
     
       11. A knitting machine part according to claim 1, wherein said knitting machine part is a sinker. 
     
     
       12. A method of knitting a yarn comprising a cut-resistant fiber, comprising: (1) providing said cut-resistant yarn;   (2) providing a knitting machine which includes a knitting machine part comprising: (i) a base substrate having a surface and having at least one yarn-contacting region for contacting said yarn during a knitting process; and   (ii) a coating disposed on the surface of at least said yarn-contacting region of said base substrate, wherein said coating comprises titanium carbonitride, said titanium carbonitride coating formed on said yarn contacting region of said knitting machine part by a chemical vapor deposition process using a deposition temperature of from about 800° C. to about 1000° C., said titanium carbonitride having a carbon-to-nitrogen weight ratio of from about 1:4 to about 4:1, further wherein the coating has a hardness sufficient to resist abrasion caused by knitting said yarn; and     (3) subjecting said yarn to a knitting process using said knitting machine such that at least said coated yarn-contacting region of said knitting machine part contacts the yarn.   
     
     
       13. A method according to claim 12, wherein said knitting machine part is a knitting needle. 
     
     
       14. A method according to claim 12, wherein said knitting machine part is a sinker. 
     
     
       15. A method according to claim 12, wherein the titanium carbonitride has a carbon-to-nitrogen weight ratio of from about 1:1.5 to about 1.5:1. 
     
     
       16. A method according to claim 12, wherein the titanium carbonitride has a carbon-to-nitrogen weight ratio of about 1:1. 
     
     
       17. A method according to claim 12, wherein said base substrate has a Rockwell-C Hardness value of from about 50 to about 55. 
     
     
       18. A method according to claim 12, wherein said surface of said base substrate of said knitting machine part is uniformly coated with said coating. 
     
     
       19. A method according to claim 12, wherein said coating has a thickness of at least about 2 microns. 
     
     
       20. A method according to claim 12, wherein said base substrate of said knitting machine part comprises an iron series metal or a hard sintered alloy. 
     
     
       21. A method according to claim 12, wherein said coated base substrate comprises carbon steel or stainless steel as the substrate, further wherein said coated base substrate has been subjected to a steel-annealing heat treatment process. 
     
     
       22. A method according to claim 21, wherein said steel-annealing heat treatment process comprises the steps of: (i) heating said coated substrate to a temperature sufficient to austentize said substrate;   (ii) quenching said austentized coated substrate at a rate such that upon tempering and cooling of the austentized coated substrate, the tempered-cooled substrate has a hardness sufficient to withstand the forces associated with knitting;   (iii) heating said quenched coated substrate to a temperature sufficient to temper said substrate; and   (iv) cooling the tempered coated substrate, whereby the cooled substrate has a hardness sufficient to withstand the forces associated with knitting.   
     
     
       23. A method according to claim 22, wherein in the steel-annealing process, the coated substrate is heated to a temperature of at least about 750° C. in step (i) to austentize the coated substrate; the austentized substrate is subsequently quenched in an inert atmosphere in a 20-bar furnace or in oil with agitation at a temperature of about 60° C. to about 200° C. in step (ii); and the quenched substrate is heated to a temperature of from about 250° C. to about 350° C. in step (iii) to temper the quenched coated substrate. 
     
     
       24. A method according to claim 22, wherein said substrate comprises a carbon steel having a carbon content of about 0.86% to about 0.95% by weight and a Rockwell-C Hardness of from about 50 to about 55. 
     
     
       25. A method of knitting a yarn, comprising: (1) providing said yarn;   (2) providing a knitting machine which includes a knitting machine part comprising: (i) a base substrate having a surface and having at least one yarn-contacting region for contacting said yarn during a knitting process; and   (ii) a coating disposed on the surface of at least said yarn-contacting region of said base substrate, wherein said coating comprises titanium carbonitride having a carbon-to-nitrogen weight ratio of from about 1:4 to about 4:1, further wherein said coating has a hardness sufficient to resist abrasion caused by knitting a yarn comprising a cut-resistant fiber; and     (3) subjecting said yarn to a knitting process using said knitting machine such that at least said coated yarn-contacting region of said knitting machine part contacts said yarn.   
     
     
       26. The method as recited in claim 25, wherein said yarn comprises abrasive fibers. 
     
     
       27. The method as noted in claim 25, wherein said yarn comprises cut-resistant fibers that comprise hard particles. 
     
     
       28. The method as recited in claim 25, wherein said yarn comprises conventional fibers. 
     
     
       29. A machine part that contacts yarn in a machine that handles, processes or manufactures yarns, said machine part comprising: (i) a base substrate having a Rockwell-C Hardness value of from about 50 to about 55, said base substrate further having a surface and at least one yarn-contacting region;   (ii) a coating disposed on the surface of said base substrate on at least the yarn-contacting region of said base substrate, wherein said coating comprises titanium carbonitride having a carbon-to-nitrogen ratio of from about 1:4 to about 4:1.   
     
     
       30. A machine part according to claim 29, wherein the carbon-to-nitrogen weight ratio is from about 1:1.5 to about 1.5:1. 
     
     
       31. A machine part according to claim 29, wherein the carbon-to-nitrogen weight ratio is about 1:1. 
     
     
       32. A machine part according to claim 29, wherein said titanium carbonitride coating has been formed on the yarn-contacting region by a chemical vapor deposition process using a deposition temperature of from about 800° C. to about 1000° C. 
     
     
       33. A machine part according to claim 1, wherein said base substrate comprises an iron series metal or a hard sintered alloy. 
     
     
       34. A machine part as recited in claim 29, wherein said machine is a knitting machine and said machine part is selected from the group consisting of needles, sinkers, sinker plates, guides, and cutters. 
     
     
       35. A machine part as recited in claim 29, wherein said machine is a weaving loom and said machine part is selected from the group consisting of guides, pins, tension disks, tension poles, drop wires, drop wire holding rods, scissors, heddles, reeds, fill insertion equipment, shuttle parts, and rapier head parts. 
     
     
       36. A machine part as recited in claim 29, wherein said machine is a yarn twisting, repackaging, or wrapping machine and said machine part is selected from the group consisting of guides, tensioning equipment, and rings. 
     
     
       37. A machine part as recited in claim 29, wherein said machine is used for beaming and said machine part is selected from the group consisting of guides and tension bars. 
     
     
       38. A machine having greater resistance to abrasion that results from handling, processing, or manufacturing abrasive yarns, said machine comprising the part recited in claim 29. 
     
     
       39. The machine recited in claim 38, wherein said machine is selected from the group consisting of knitting machines, weaving looms, yarn twisting machines, yarn repackaging machines, yarn wrapping machines, and beaming equipment. 
     
     
       40. A knitting machine part produced according to the process of: (A) providing a base substrate comprising stainless steel or carbon steel having a carbon content of about 0.86% to about 0.95% by weight, said base substrate having a surface with at least one yarn-contacting region for contacting yarn during a knitting process;   (B) coating said at least said yarn-contacting region of said base substrate, wherein said coating comprises titanium carbonitride having a carbon-to-nitrogen weight ratio of from about 1:4 to about 4:1 and said coating has a hardness sufficient to resist abrasion caused by knitting said yarn; and   (C) subjecting said coated base substrate to a steel-annealing heat treatment process comprising: (i) heating said coated substrate to a temperature of at least about 750° C. to austentize said substrate;   (ii) quenching said austentized coated substrate in an inert atmosphere in a 20-bar furnace or in oil with agitation at a tempaerature of about 60° C. to about 200° C., said quenching performed at a rate such that upon tempering and cooling of the austentized coated substrate, said tempered-cooled substrate has a hardness sufficient to withstand the forces associated with knitting;   (iii) heating said quenched coated substrate to a temperature of from about 250° C. to about 350° C. to temper said substrate; and   (iv) cooling the tempered coated substrate, whereby the cooled substrate has a Rockwell-C Hardness of from about 50 to about 55.     
     
     
       41. A method for coating metal parts comprising: (a) providing a metal substrate comprised of a metal selected from the group consisting of carbon steel and stainless steel;   (b) coating at least one surface of said substrate with a composition comprising titanium carbonitride wherein said coating is formed on said surface by a chemical vapor deposition process using a deposition temperature of from about 800° C. to about 1000° C., said composition having a carbon-to-nitrogen weight ratio of from about 1:4 to about 4:1; and   (c) subjecting said coated substrate to a steel-annealing heat treatment process.